


Undercover, Underwear?

by luckystars1015



Category: Gintama
Genre: Bondage, Bottom!Hiji, Crossdressing, Exhibitionism, Explicit Sexual Content, Fake Dating, Hijikata in Drag, M/M, Oneshot, Plot What Plot/Porn Without Plot, Top!Gin, Voyeurism, drug mention, undercover police work
Language: English
Status: Completed
Published: 2019-05-12
Updated: 2019-05-12
Packaged: 2020-03-01 09:54:12
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,485
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18797998
Author URL: https://archiveofourown.org/users/luckystars1015/pseuds/luckystars1015
Summary: "It had to be prank. Hijikata was seriously not standing in Kabukicho on the coldest night in a gold sparkling sequin dress that only went down to his thighs, right? The dress was strapless, barely held up with a prayer around his chest. With the way the neon lights bounced off the sequins of his dress, he felt like a walking disco ball. This just had to be his worst nightmare wrapped up in a fever dream."Hijikata and Gintoki go undercover for a sting operation as lovers to stop the biggest drug deal of all time. But as Hijikata learns tonight, nothing ever goes as planned.





	Undercover, Underwear?

**Author's Note:**

  * Inspired by [Monsters Are to Be Loved](https://archiveofourown.org/works/7031881) by [Rison_Iinekin_Tyaedairgue (Lack_of_Common_Sense)](https://archiveofourown.org/users/Lack_of_Common_Sense/pseuds/Rison_Iinekin_Tyaedairgue). 



Hijikata was going to kill Yamazaki. He swore to all the gods of the known universe that he will ensure that Yamazaki would exhale his last breath before the sun rose. 

 

The demon vice-commander of the Shinsengumi gave that nimrod of a subordinate  _ one _ task. One small task that even a monkey couldn’t have messed up. Get him a girl’s outfit. In the craziness that led up to this undercover investigation, he hadn’t had the time to specify what he had wanted. It was obvious to Hijikata though. Something simple that most Japanese women wore. What Hijikata had imagined was a traditional yukata with maybe some anpan to serve as fake boobs. That was the path that he thought Yamazaki’s mind would take. 

 

It  _ had _ to be prank. Hijikata was seriously not standing in Kabukicho on the coldest night in a gold sparkling sequin dress that only went down to his thighs, right? The dress was strapless, barely held up with a prayer around his chest. Not only did Yamazaki pick the worst dress in existence, he chose one three sizes too small. The last but not the least inane part of his dress was a small belt, which seemed to mock him with its existence. What was it holding up?! His pride?! That had gone down the drain the moment the dress’s sparkles attacked his eyes. With the way the neon lights bounced off the sequins of his dress, he felt like a walking disco ball. This just had to be his worst nightmare wrapped up in a fever dream.

 

How did he end up in this position again? Oh that’s right––it was because he was an anal retentive workaholic. He had refused to hand this case over to anyone. It was the most important case that had ever crossed the Shinsengumi’s desk. The most notorious drug dealer in nine galaxies was arriving on Earth to introduce a narcotic that would send the streets of Edo into total chaos. For months, Hijikata had worked the case, setting up a sting operation at Snack Smile, the only location that his deputy chief had approved of. 

 

This meant that Kondo was the last person on earth to go undercover because even a whiff of Otae, who worked as a hostess there, would transform the gorilla into a blithering idiot. And of course, he wouldn’t hand it over to Sougo. That asshole would blow the operation simply out of spite. That left the future of Japan in the hands of the one remaining sane member of the Shinsengumi: Hijikata Toshiro, who so desperately wished he could replace all the officers of the Shinsengumi with clones of himself. All of Edo’s filth would be wiped out in a week. 

 

A cold wind carried a wolf-whistle over to Hijikata and he would have killed the culprit on the spot if his weapons hadn’t been confiscated from him before the operation started. Since he was the one to insist that he would lead the sting, it had been pointed out that his face and figure was one of the most recognizable in Kabukicho. There was no way his cover wouldn’t have been blown the moment he walked through the door. 

 

Someone–fucking Sougo–had suggested that he dressed up as a girl. No one in a million years could ever guess that the Demon Vice Commander of the Shinsengumi would walk the streets of Kabukicho in drag. So it was unanimously decided for him that he would be thrown into the streets in high heels and a black-haired wig that flowed down to the back of his waist. The only thing keeping him warm at this point, since his dress was as thin and useless as paper, was his blood-boiling rage. 

 

A figure bumped into Hijikata and the black-haired man almost toppled over like the Towel of Babel in these impossible heels. How the hell did women walk on a daily basis in these torture devices?! The inventor of these shoes had to hate feet! And no sane creature would wear these to look hot. All women were just crazy!

 

“Oh--sorry. Didn’t mean to bump into you.”

 

Hijikata’s blood ran cold as the familiar lazy drawl hit him. He hadn’t asked God to make his life worse. But God answered him anyway by conjuring up the bane of Hijikata’s existence. 

 

“I’m supposed to meet someone here. Have you seen him? Nicotine freak with a mayo fetish? About yea high?” The silver-haired bastard said as he raised his hand next to his head, indicating the height. 

 

The Yorozuya idiot looked more like a sleazebag than usual. He was dressed in a black suit over a wine red shirt that he was too lazy to button to the collar, exposing his pale collarbones (not that Hijikata was one to notice or anything).

 

Hijikata yanked the Yorozuya asshole by his tie and glared at him with a look that could vaporize smaller prey. “Is that how you’ve been introducing me, you diabetic asshole? I’ll kill you right now for insulting a police officer.” Hijikata knew something as minor as that wasn’t a punishable offense. But maybe he could write off Yorozuya’s death as an accidental casualty after he wrapped up this case. 

 

For the first time since Hijikata had known him, the dead fish-eyes of the silver-haired samurai widened in shock. “Mayora?!” 

 

The vice chief punched Gintoki for his blunder. “Shut up!” Hijikata whisper-shouted. “You’re here to help the operation! Not hurt it!” 

 

This harebrained idiot picking his nose was the only reason that the cabaret owner had agreed to the Shinsengumi’s request in the first place––something about owing Yorozuya a favor. Gintoki would unfortunately be more involved in the case than Hijikata was comfortable with. Since Hijikata was an officer of the law, it would be considered entrapment if he were the one to ask for the drug deal. So they chose the next best thing. ‘Best’ was stretching it. He was the only one willing and available to participate on this night. The silver-haired idiot would be leading the deal while Hijikata sat next to him as his “delicious side dish” (Sougo’s words, not his), making sure everything went according to plan. 

 

Gintoki let his eyes generously take in the visage that was Hijikata. Although his face was blank, he couldn’t believe that it was the mayo freak before him. He longed to card his fingers through the long, silky locks cascading down the chainsmoker’s back. The poor excuse for a dress clung desperately to Hijikata’s muscular figure, showing of a tight waist that he never noticed since it was typically hidden under his baggy uniform or loose yukata. 

 

Gintoki had gone into a bathhouse with Hijikata, seeing the man with much less clothes. But now, he was looking at Hijikata under a new light. These new neon lights of Kabukicho made it irresistible for Gin to  _ not _ ogle his rival’s toned legs. His eyes trailed back up from Hijikata’s calves to settle upon his dolled up face. Was that eyeliner? It had to be since Hijikata’s crystal blue eyes popped more than usual (not that Gintoki noticed or anything). 

 

“Who did your makeup?”

 

“Sougo,” Hijikata begrudgingly spat out. “We agreed never to talk about it again.” Mitsuba had loved to experiment new makeup techniques she found on MeTube on her poor, hapless brother. 

 

Hijikata crossed his arms to shield himself from the cold. He huffed in embarrassed indignation, “call me Toshiko.”

 

Not allowing Gintoki the chance to tease him for the name, he tried to storm off toward the front entrance of the Snack Shack but instead almost fell face-first as his heel got lodged in a crack. Instead of meeting a cruel fate with the ground, warm arms wrapped around Hijikata to steady him. 

 

“Whoaaa, careful there, Toshiko-chan.”

 

The blush lighting Hijikata’s face was no longer due to the cold. 

 

“Want some help?” Gintoki uncharacteristically offered like a gentleman, holding his elbow out for Hijikata to take hold of. 

 

Hijikata narrowed his eyes in disgust. Instead he bent down, took off his heels, and chucked them at a herd of drunk bastards without any remorse. His bare feet slammed against the cold pavement as he made his way up to the doors of the cabaret. 

 

Gintoki whistled in appreciation as he tilted his head to catch a view of Hijikata’s tight ass as he went up the stairs. He hated seeing Hijikata go, but man did he love watching him leave. 

 

At the start of this night, the Yorozuya boss had been brainstorming all the ways he could milk the Shinsengumi of rewards. A year worth of parfaits at his favorite restaurant. Two year subscription to Jump. If the criminal was as high-profile as they alluded to, he knew that the success of the investigation would trickle down to himself as well. 

 

But the moment he recognized the steel blue eyes of the Mayora freak, seething in glossy red lipstick, he genuinely felt that the sight of Hijikata in that impossibly tight dress was payment enough. 

 

The two were led up two flight off stairs to a private luxury suite. The room itself wasn’t too big as it functioned as a soundproof karaoke room. Low jazz music was playing in the background, which made the setting even weirder for the narcotic deal of the century to take place. The dim lighting made it difficult to make out details of the two occupants in the room. When their eyes finally adjusted, they saw two human-like amantos with teal skin and pointy ears. It looked like these aliens had walked straight out of a Star Trek convention. 

 

The one that was obviously the boss was heavier-set and sat with his shoulders squared, giving off a imposing aura. A skinny inconsequential figure flanked his side. 

 

The two slipped into the both, careful to not knock into the square table that reached their knees. This was barely any space in this tight room and Hijikata could sit nowhere except right next to Gintoki, his unclothed knees touching the silver samurai. Hijikata tried to adjust his dress that had ridden up his thighs without calling too much attention to himself. But little did he know, all eyes were glued on him. 

 

“Let’s get to business,” Gintoki said, coughing to get everyone’s attention to jumpstart this meeting. If they didn’t finish soon, he was going to go crazy being in such close proximity to Hijikata, which he never thought he’d say in a non-fighting kind of way. He definitely wanted to wrestle the black-haired samurai right now. But not in the way they usually did. He preferred to wrestle in bed. With no clothes. 

 

“I’m Gin-san, the Shadow King of Kabukicho.” 

 

Hijikata used every ounce of self-restraint to not roll his eyes. This wasn’t Dragon Quest. 

 

“This lovely lady right here is my girlfriend, Toshiko-chan,” Gintoki said, taking the opportunity to stroke Hijikata’s thigh. The chain smoker was one popped vein away from punching Gintoki in the throat for feeling him up. He was laying it on a bit thick. 

 

It was the exact opposite of what Hijikata was doing, which was literally keeping his mouth shut for fear of misstepping. He looked completely pissed off and constipated. He knew his eyebrows were furrowed to the point that it looked like another V sat below his V-shaped bangs. But he couldn’t help it! He was a police officer, not an actor! If he had any talent for this shit, he would have joined a theater group and not the Shinsengumi. 

 

“Sorry about Toshiko-chan over here. It’s our anniversary tonight and she’s pissed I had to take care of business instead. I hope you don’t mind her being here.”

 

Wow. That bastard really could pull out anything out of his ass. 

 

“It’s no problem. It’s actually rather nice to have such a beautiful lady freshen up the room,” the dealer said before sending Hijikata the ickiest wink on Earth. The cross dressing black-haired man suppressed a full body shudder. He suddenly felt a wave of sympathy for the girls down in the first floor of the cabaret who had to do this for a living. 

 

The Amanto boss continued, “I don’t make deals with just anyone. You have to be pretty special to catch my eye.” The side glance that he shot Hijikata was not missed by anyone in the room. 

 

“That’s understandable. But how do I know you have the real thing,” Gintoki interjected, wanting to take back the control of the situation. 

 

The dealer smirked and made a slight gesture with his hand, motioning for his servant to slide a small case across the table. 

 

“Why don’t you have a sample? Be careful though, the first hit takes you out for two days after you come down from the high.”

 

Gintoki opened the case and found several small beads of black crystal. They looked no different from candy you could buy from the convenience store. A slight tap on his shoe from Hijikata’s foot confirmed that these were indeed the merchandise. 

 

“No thanks. I’ll take your word.”

 

The dealer spoke again, “usually I require a proof of payment, say 10 million yen up front, before I agree to the transaction. But tonight I feel particular generous after beholding the beauty of your woman.”

 

Hijikata did  _ not _ like where this was going. 

 

“Think of it as a small entertainment fee,” the Amanto started. 

 

“What kind of entertainment? I know a few card tricks. I am quite good with my hands,” replied Gintoki, throwing up jazz hands for the heck of it. 

 

“Fuck your girlfriend in front of me.”

 

Hijikata should have known this meeting was gonna go to shit the moment he noticed the automatic lube dispenser next to Gin’s head. What little self-control he had remaining snapped like a twig and the undercover officer made a move to lunge at the perverted freak and tear out his throat. But Gintoki stopped him in his tracks, wrapping his strong arms around his waist and crushed Hijikata to his side. He repositioned his one hand to clutch the black-haired man’s jaw.

 

Gintoki, in another surprising move, began running his hand up and down Hijikata’s waist in an effort to calm him down. Despite himself, Hijikata relaxed, allowing his body to melt into Gintoki’s muscular frame. 

 

It was odd. Although the two men were off similar heights and build, Hijikata had a much smaller, almost delicate waist. Gintoki couldn’t help but felt like Hijikata was made to fit into his side like a puzzle piece. 

 

The dealer smile grew wider, entranced at the scene. “How about I up the ante? I’ll have my other subordinate wheel 100 kilos of the crystals to the back of the building if you decide to do the show. Consider it a first-time customer appreciation gift.”

 

Gintoki smirked. The Yorozuya bastard began trailing a line of kisses from Hijikata’s wrist up to his neck, pausing a couple kisses in between to say, “Toshiko will do whatever I say... because what I want... is what  _ you _ want... isn’t that right, Toshiko-chan?”

 

Hijikata got the hint. Anything for this mission, right? He nodded, still entrapped in Gintoki’s vice grip. 

 

Gintoki thanked him by sweeping Hijikata’s long hair behind him and sucking on the junction of his jaw and neck. The demon vice chief could not keep the whimper of pleasure from escaping his lips. 

 

Without warning, Gintoki grabbed the chainsmoker by the waist and placed him right in front of his lap. He hooked his hand underneath both of Hijikata’s knees, spreading the Mayora’s legs apart by placing them on either side of his legs. The poor Hijikata instinctively shoved his hands to hold down the dress, not wanting to be so exposed.

 

“Come on, Toshiko-chan. You have nothing to be embarrassed about.” Gintoki licked the outer shell of Hijikata’s blushing earlobe. Growing impatient, he untied the thin belt around Hijikata’s waist and tied it around his wrists. What a convenient new use for the belt. It looked much better around Hijikata’s wrists than his waist anyhow. Gintoki pulled his hands away and took the freedom to pull the dress up, further exposing Hijikata to the cold air. Hijikata’s face was hot with embarrassment. 

 

“Toshiko-chan,” Gintoki asked slowly in disbelief, discovering the biggest surprise of the evening, “are you… not wearing any underwear?”

 

Hijikata’s face got impossibly redder. “I-I didn’t want to!”

 

His admission made it all the more worse. It was true. He didn't want to wear any underwear tonight. But that was because of the options he was given! Someone—definitely Sougo—had given him a thong instead of any real underwear. He could either wear that or stick with his mayo-printed boxers, but those stuck out of the dress since it was so stupidly short! The best option was to wear nothing at all instead of that pathetic excuse for an under garment! What is it with women and wearing next to nothing?!

 

The silver-haired samurai chuckled darkly into Hijikata’s ears. He was growing more fiendish by the second, falling easily into the trappings of his role as Toshiko’s criminal boyfriend. He lightly ran his fingers up Hijikata’s thigh before slowly wrapping his hands around the flushing man’s dick. With the other, he placed it under the automatic lube dispenser before moving to the chainsmoker’s most vulnerable place. 

 

Hijikata hissed sharply when he felt the insufferable bastard’s finger breech his hole. Gintoki pushed his finger up to the first knuckle before pressing against his tight walls, earning another delightful hiss from the black-haired crossdresser. Not forgetting Hijikata’s other special part, he began stroking it, bringing it to life. 

 

The two voyeurs in the room watched the scene with rapt attention, not being able to take their eyes off even if the ground splitted beneath their feet. Toshiko’s every reaction was just that mesmerizing. At this point, Hijikata had closed his eyes, too mortified to acknowledge the two pervert aliens watching him get fingered. He focused all his senses on Gintoki’s heated touches. 

 

“So what made you finally decide to introduce your product to Earth?” Gintoki asked, making an odd attempt of normal conversation as he continued doing unspeakable things to his partner. 

 

The dealer licked his lips, not removing his eyes off the ministrations Gintoki was performing on the man he claimed to be his girlfriend. “Oh, I recently bought the rights to an abandoned processing plant on Mars. There’s barely any type of governance or trade regulation, so I’m planning to employ Amantos and humans alike there. I can practically pay them next to nothing and they won’t even care. The trick is to make them slightly addicted to crave such a highly coveted job, allowing them to be close to the crystals, but keep them sane enough to know the consequences of crossing me and taking the product for themselves.” The dealer couldn’t help but give a maniacal laughter like one of the villains of a children movie, mentally patting himself on the back for his diabolical plan. 

 

By the end of his long-winded speech, Hijikata was fully hard and stretched enough to allow a second finger in. When Gintoki decided to switch it up and scissor his fingers and spread Hijikata more, the poor undercover cop lost all sense of dignity and began filling the room with his unabridged moans. Even the Demon Vice Commander of the Shinsengumi couldn’t believe that such whorish moans were coming from himself. 

 

“Shhhh… quiet, baby. The men are talking,” Gintoki said into Hijikata’s ears before taking his hands off his dick to insert two fingers in the chainsmoker’s mouth to effectively stifle his moans. 

 

He returned to the conversation at hand. “But how do you plan to transport such large amounts of the drugs to Earth? I’m worried about my supply being cut off.”

 

“That’s a valid concern, but you needn’t worry. I have a special  _ friend _ at the Department of Amanto Imports who is willing to turn a blind eye to our business transactions, for a price, of course. Part of the transaction fee will be paid to him. You’ll get a rather handsome distribution bonus as part of our contract. The more people you get addicted to the crystals, the better business will be for the both of us.”

 

Hijikata knew he should be listening to this. But all that filled his mind was the pleasurable burning sensation of his lower half. It felt like magma was pooling in his abdomen and every jab of Gintoki’s fingers sent a sweet stab up his spine. His moans grew louder despite the two fingers shoved into his mouth. His tongue couldn’t help but twist itself around them, coating the digits in saliva. 

 

Somehow Hijikata just knew the silver-perm bastard was smirking in delight. He withdrew his sticky fingers from Hijikata’s mouth and pulled down the top of his dress. Gintoki circled his fake lover’s nipples, dragging a nail across the bud, before pinching it with a bit of pressure. The sensation went straight to Hijikata’s dick and he squirmed, pressing his ass against the undeniable boner tenting Gintoki’s pants. 

 

Not fair. This was completely unfair. He was completely helpless Gintoki’s hands and he could do nothing about it. The conversation continued, with the dealer revealing massive amounts of information, moreso due to the hypnotizing pull Hijikata’s body had on the amanto. 

 

When he no longer felt that the three fingers pumping and spreading into him were enough to scratch that itch deep inside his body, he whined out in a desperate tone.

 

“G-Gin-san…  _ please… _ I can’t take it anymore,” Hijikata begged, his cock dripping to prove his point. 

 

A maddening smirk crossed Gintoki’s face, his pride surging at the fact that Hijikata finally said his name after all these years. Can’t believe it took fingering him in front of an audience to get to this point. But hey, no couple was perfect, right?

 

Gin stopped his ministration to pull Hijikata into a searing kiss. “Anything for you, Toshiko-chan.” He swirled his tongue around Hijikata’s own before sucking it in his mouth. He pulled away with a sick, wet pop, thrilled at the trail of saliva connecting them. His breath was knocked out of him when he saw Hijikata’s face, lost in ecstasy with red lipstick smeared wildly across his lips from the abuse under Gintoki’s fingers and tongue. He couldn’t believe that he turned the tsundere Vice Commander into a such a wanton mess. 

 

Wasting now time, he manhandled Hijikata onto the tabletop. Gin didn’t even bother with the belt around Hijikata’s wrist, so the chainsmoker had no choice but to balance precariously on his knees and elbows. 

 

Thankfully the table was wide enough so that a meter of space separated Hijikata and the two alien voyeurs. With the low height of the table, Hijikata’s ass perfectly aligned with Gintoki’s dick. The silver-haired samurai got a handful of lube from the dispenser and gave his dick a few experimental strokes. He slowly pushed the tip past Hijikata’s ring, hissing at the velvety heat closing around his swollen cock. 

 

Gintoki squeezed his eyes shut, focusing all his senses on the tight, wet heat that wrapped his dick. After a few moments searing the sensation into his spank bank for future use, he slowly pulled out, relishing in the whine from Hijikata, and shoved himself back in to the enticing man’s delicious heat. Hijikata’s body was more addictive than any narcotic that would ever cross his path. 

 

Hijikata couldn’t hold back his lustful moans, indulging in the fact that his lewd sounds were echoing off of the walls. Gintoki pounded lightning-hot pleasure into the black-haired samurai like a fucking piston, and at this point, he reveled in the fact that he had an audience to the obscene pleasure he was boiling in. 

 

The smaller amanto, growing careless from the aphrodisiac that was Hijikata, reached his hand tentatively, desiring nothing more than to stroke the lovely man’s face. He wanted to feel this angel of lust for himself. But the silver-haired samurai caught his hand a hair's-breadth away from Hijikata’s face. The dealer’s weak assistant screamed in agony when Gintoki crushed the bones in his hands as he glared at him with a possessive look that promised the worst kind of death if he tried to touch Hijikata again. Gintoki never stopped pounding into his lover all the while. 

 

His undercover lover found that one  _ spot _ that had Hijikata seeing stars in his eyelids and he moaned all the more, commanding Gintoki to go “harder!  _ Harder!  _ HARDER!”

 

Gintoki took heed of the Hijikata’s shameless demands and hit that one spot over and over and over again. The promiscuous man below thanked him by squeezing him even tighter. Not able to control himself, the Yorozuya boss breathlessly called out Hijikata’s real name as he repeatedly drilled into him. 

 

“Toshi!  _ Toshi _ ! TOSHI!”

 

Hijikata shouldn’t have found as much as pleasure as he did when he heard his name being grunted like that from Gintoki. But that was the last straw which sent Hijikata over the edge. Searing-hot pleasure rippled through his body in shockwaves with Gintoki following soon after, filling Hijikata to the brim with his come. Hijikata’s limbs gave out after coming untouched, melting into the hard table beneath him. 

 

Gintoki regarded their audience once more and asked, with some semblance of rationality, “wow, that was sure amazing. Why don’t we celebrate with a bottle of Dom Peri? It’s Toshiko-chan’s favorite.”

 

The shellshocked dealer nodded as if hypnotized, still processing the filthy, euphoric scene that just took place before his very eyes. He picked up the phone from the wall and called the bar downstairs, “can I get an order of Dom Peri?”

 

On the other line, Kondo replied, “coming right up, sir.” When he hung up, he turned around to speak to the Shinsengumi squad. “That’s the signal. Let’s storm the place.”

 

Gintama reluctantly removed himself from his beloved Toshiko-chan. His eyes trailed down the wetness dripping sinfully between Hijikata’s legs. “I’m going to help Toshiki-chan freshen up.” With that said, he fixed his crossdressing lover’s short dress to give him some decency and placed his suit jacket around Hijikata to hide his figure from prying eyes. The silver-haired samurai maneuvered the sexually exhausted Hijikata into his arms. His lover’s eyes were still dazed, not processing anything beyond Gintoki’s touch. 

 

Hijikata allowed himself to be wrapped in Gintoki’s warmth and he fell asleep, his head nestled against the silver samurai’s shoulders. Carrying his black-haired lover out of the room, Gintoki left through a secret passage leading out onto the dark streets of Kabukicho. He bypassed the storming Shinsengumi officers just in time, saving the Demon Vice Commander from any sort of embarrassment. 

 

From now on, Toshiko-chan was just for his eyes only.


End file.
